What is limestone mad of? how is it possible that limestone can be found in area of dry land?

What is limestone made of?

Limestone is formed in two ways. It can be formed with the help of living organisms and by evaporation. Ocean-dwelling organisms such as oysters, clams, mussels and coral use calcium carbonate (CaCO3) found in seawater to create their shells and bones. The water pressure compacts the sediment, creating limestone.

How is it possible that limestone can be found in area of dry land?

Limestones are common in Kansas. They are usually found where seas once covered the land. They also can be formed from deposits in freshwater or on dry land, but nonmarine limestones are less common. Most of them were formed from accumulations of marine plants and animals after they died and sank to the sea floor. If conditions were right, millions of tons of plant and animal debris were deposited and eventually compacted together. When the sea dried up, large slabs of rock were formed, often stretching for hundreds of miles in every direction. Some plant and animal remains, such as shark's teeth and dinosaur bones, have been preserved as fossils in limestone.

Hope this helped !

option c is the correct answer.